JPH10306161A - Polyimide resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin being soluble in organic solvents and mineral acid or alkali solutions by selecting a resin entirely consisting of structural units containing a triphenylamine group or of at least a specified proportion of such structural units and the balance of structural units derived from 4,4- diaminotriphenylamine. SOLUTION: There is provided a polyimide resin comprising structural units represented by formula I (wherein A is a tetravalent organic group) and formula II or comprising at least 30% structural units represented by formula I and the balance of structural units derived from 4,4-diaminotriphenylamine. This resin should have an inherent viscosity of 0.1-3 dl/g and a glass transition point of 320 deg.C or above. It is produced from a hydroxytriphenyldiamine compound represented by formula III (e.g. 4,4-diamino-4-hydroxytriphenylamine) and a tetracarboxylic dianhydride represented by formula IV (wherein A is a tetravalent organic group) (e.g. pyromellitic dianhydride).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyimide resin, and more particularly, to a polyimide resin having a particularly high glass transition temperature, excellent heat resistance, and being soluble in various organic solvents and mineral acids or alkali solutions. A novel polyimide resin having

[0002]

2. Description of the Related Art Polyimide resins are known as engineering plastics having excellent heat resistance, electrical properties and mechanical properties, and have been widely used as protective materials, insulating materials or structural materials in the field of electronic equipment. I have. However, many of these polyimide resins are insoluble in any of various organic solvents and mineral acids,
Also, since it is thermally infusible, it was extremely difficult to perform the molding.

[0003]

The above-mentioned conventional aromatic polyimide resins have a high glass transition temperature and excellent heat resistance, and at the same time have good solubility in organic solvents and mineral acids. There are few things,
The fact that there is little aromatic polyimide resin having both such heat resistance and processability has been a major problem in commercial use of this resin. In order to solve such a problem, in recent years, for example, a soluble polyimide resin having a triphenylamine structure (Japanese Patent Laid-Open No. 4-11631) has been proposed. However, compared with the conventional polyimide resin, it has a problem that the heat resistance is not sufficient.

An object of the present invention is to provide a novel polyimide resin which is excellent in heat resistance and is soluble in various organic solvents and mineral acids or alkali solutions without impairing the characteristic of having a high glass transition temperature inherent to the polyimide resin. Is to provide.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the problems of the prior art, and as a result, the specific structural units represented by the above general formulas (1) and (2) have been obtained. Is a polyimide resin represented by the general formula (1)
At least a specific percentage of the structural unit represented by
It has been found that a polyimide resin comprising a structural unit derived from 4'-diaminotriphenylamine has a high glass transition temperature, is excellent in heat resistance, and is soluble in various organic solvents, mineral acids or alkali solutions. The present invention has been accomplished.

That is, the invention of claim 1 of the present invention is a polyimide resin comprising a structural unit represented by the following general formula (1).

[0007]

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According to a second aspect of the present invention, there is provided the polyimide according to the first aspect, wherein the polyimide comprises a structural unit represented by the following formula (2).

[0009]

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According to a third aspect of the present invention, there is provided the polyimide resin according to the first or second aspect, wherein the inherent viscosity of the polyimide resin measured at 30 ° C. in a 98% concentrated sulfuric acid at a concentration of 0.5 g / dl is 0. 1 to 3 dl / g.

[0011] The invention of claim 4 of the present invention comprises 30% or more of the structural unit represented by the general formula (1) of claim 1;
The remainder is a polyimide resin comprising a structural unit derived from 4,4′-diaminotriphenylamine.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The polyimide resin of the present invention is produced using a hydroxytriphenyldiamine compound represented by the following formula (3) and a tetracarboxylic dianhydride represented by the following general formula (4) as raw materials, or It is manufactured using a hydroxytriphenyldiamine compound represented by 3) and a tetracarboxylic dithioanhydride represented by the following general formula (5) as raw materials.

[0013]

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[0014]

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[0015]

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The hydroxytriphenyldiamine compound represented by the above formula (3) is 4,4'-diamino-
4 "-Hydroxytriphenylamine, which can be easily produced using, for example, p-halonitrobenzene and 4-benzyloxyaniline as starting materials. Specifically, for example, 4-benzyloxyaniline and p-benzyloxyaniline
Chloronitrobenzene in dimethyl sulfoxide
After reacting at 00 ° C. and recrystallizing the obtained compound,
It is obtained by reducing with zinc and hydrochloric acid and further neutralizing with weak alkali.

Specific examples of the tetracarboxylic dianhydride represented by the above general formula (4) include, for example, pyromellitic dianhydride, 3,4,3 ', 4'-biphenyltetracarboxylic acid Dianhydride, 3,4,3 ′, 4′-diphenylethertetracarboxylic dianhydride, 3,4,3 ′,
4'-benzophenonetetracarboxylic dianhydride, 3,
4,3 ′, 4′-diphenylsulfonetetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane Anhydride, 3,4,3 ", 4" -terphenyltetracarboxylic dianhydride and the like can be exemplified. These tetracarboxylic acids may be used alone or in combination of two or more.

The tetracarboxylic dithioanhydride represented by the above general formula (5) is specifically, for example, pyromellitic dithioanhydride, 3,4,3 ', 4'-
Biphenyltetracarboxylic dithioanhydride, 3,4
3 ', 4'-diphenylethertetracarboxylic dithioanhydride, 3,4,3', 4'-benzophenonetetracarboxylic dithioanhydride, 3,4,3 ', 4'-diphenylsulfonetetra Carboxylic acid dithio anhydride, 2,2-
Bis (3,4-dicarboxyphenyl) -1,1,
Examples thereof include 1,3,3,3-hexafluoropropanedithioanhydride and 3,4,3 ", 4" -terphenyltetracarboxylic dithioanhydride. These tetrathiocarboxylic acids may be used alone or in combination of two or more.

As an example of the first method for producing the polyimide resin of the present invention, the diamine compound and the tetracarboxylic dianhydride are reacted in an organic solvent at -20 to 50 ° C. for several minutes to several days. Thus, a polyamic acid is obtained, and then a polyimide resin is obtained by heating or treating with a dehydrating ring-closing agent. Examples of the organic solvent that can be used for the polyamic acid synthesis reaction include amide solvents such as N, N-dimethylacetamide and N-methyl-2-pyrrolidone, benzene, anisole, diphenyl ether,
Aromatic solvents such as nitrobenzene, benzonitrile, pyridine, chloroform, dichloromethane, 1,2-
Examples thereof include halogen solvents such as dichloroethane and 1,1,2,2-tetrachloroethane, and ether solvents such as tetrahydrofuran, dioxane and diglyme. In particular, N, N-dimethylacetamide,
When an amide solvent such as N-methyl-2-pyrrolidone is used, a high-polymer polyamic acid can be obtained.

Then, the obtained polyamic acid is added with 200 to
Heat at 350 ° C. to obtain a polyimide resin. In addition, a polyimide resin can be obtained by treating a polyamic acid with a dehydrating ring-closing agent such as a mixed solution of acetic anhydride and pyridine.

In this method, the molecular weight of the polyimide resin of the present invention is limited by the amount charged with the diamine compound, and a high molecular weight polyimide resin can be produced when used in an equimolar amount.

An example of the second method for producing the polyimide resin of the present invention is as follows. In an organic solvent, the diamine compound and the tetracarboxylic dithioanhydride are reacted at 20 to 200 ° C. for several minutes to several days. To obtain a polyimide resin. Examples of the organic solvent that can be used for the synthesis reaction of the polyimide include amide solvents such as N, N-dimethylacetamide and N-methyl-2-pyrrolidone;
Aromatic solvents such as benzene, anisole, diphenyl ether, nitrobenzene, benzonitrile, pyridine, halogen solvents such as chloroform, dichloromethane, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, tetrahydrofuran , Dioxane, and diglyme. In particular, when an amide-based solvent such as N, N-dimethylacetamide or N-methyl-2-pyrrolidone is used,
A high-polymer polyimide can be obtained.

In this method, the molecular weight of the polyimide resin of the present invention is limited by the amount charged with the diamine compound, and a high molecular weight polyimide resin can be produced when used in equimolar amounts.

In the polyimide resin of the present invention, 98%
The inherent viscosity measured at a temperature of 30 ° C. and a concentration of 0.5 g / dl in concentrated sulfuric acid is not particularly limited, but is 0.1 to 3 dl.
/ G is preferred, and more preferably 0.2 to 2 dl / g. This is because the inherent viscosity is 0.1 dl / g.
If it is less than 3, the properties such as mechanical properties and heat resistance of the molded article formed into a film or the like are not sufficient, and if the inherent viscosity exceeds 3 dl / g, the solubility in an organic solvent or the like becomes poor.

The polyimide resin of the present invention thus produced is soluble in a mineral acid such as sulfuric acid. Further, the solubility of the tetracarboxylic acid dianhydride derivative represented by the general formula (4) and the tetracarboxylic dithioanhydride derivative represented by the general formula (5) depends on the kind of the used production method and the used tetracarboxylic acid dithioanhydride derivative. However, in some resins, N-methyl-2-pyrrolidone, dimethylimidazolidinone, dimethylsulfoxide, metacresol, orthochlorophenol, pyridine, etc. Become.

The polyimide represented by the general formula (2) includes, for example, organic amines such as tetraammonium hydroxide and triethanolamine, alkaline aqueous solutions such as sodium hydroxide and potassium hydroxide, sodium phosphate and potassium phosphate. All or a part of it becomes soluble in alkali metal phosphates of the above.

Further, the polyimide resin of the present invention has 320
Since it has a high glass transition point of at least ℃, it is thermally stable and has excellent heat resistance.

The polyimide resin of the present invention contains 30% or more, preferably 4%, of the structural unit represented by the above general formula (1).
0% or more, more preferably 50% or more, with the balance being 4,
It includes a polyimide resin comprising a structural unit derived from 4'-diaminotriphenylamine. If the content of the structural unit represented by the general formula (1) is less than 30%, the heat resistance is inferior.

The polyimide resin of the present invention may be blended with other resins such as a polyamide resin and a conventional polyimide resin, and various additives, as long as the properties are not impaired.

[0030]

Next, the present invention will be described in detail with reference to examples and comparative examples, but the present invention is not limited to these examples unless departing from the gist of the present invention.

Example 1 4,4′-diamino-4 ″-
0.595 g of hydroxytriphenylamine (0.02 g)
0 mol) was dissolved in 10 ml of N, N-dimethylacetamide, and 0.601 g (0.020 mol) of 3,4,3 ′, 4′-biphenyltetracarboxylic dianhydride was dissolved in a solid at a time. added. After stirring at 25 ° C. for 12 hours, the viscous polymerization solution was cast on a glass plate and dried at room temperature under reduced pressure of about 30 torr for one day. On the other hand, the reaction solution was poured into 350 ml of methanol to obtain a solid of polyamic acid. The polyamic acid film formed on the former glass plate was placed at 100 ° C. for 1 hour for 2 hours.
Heat treatment was performed at 00 ° C. for 1 hour and at 300 ° C. for 1 hour under a nitrogen stream to obtain a polyimide resin film. According to the infrared absorption spectrum of polyimide resin (film), 17
Absorption of the carbonyl group of the imide bond were observed respectively in 80 cm ^-1 and 1725 cm ^-1. The inherent viscosity of the obtained polyimide resin was 0.32 dl / g (9
Measured in 8% concentrated sulfuric acid at 30 ° C. at a concentration of 0.5 g / dl.
Hereinafter the same). The inherent viscosity of the polyamic acid was 0.30 dl / g (in dimethylacetamide,
The measurement was performed at 30 ° C. and a concentration of 0.5 g / dl. Hereinafter the same). The glass transition temperature of the obtained polyimide resin was 388 ° C. as shown in Table 1 as measured by a differential scanning calorimeter, and the 10% weight loss temperature by a thermogravimeter was 511 ° C. in air, nitrogen Medium temperature was 536 ° C.
Table 2 shows the solubility of the obtained polyimide resin in a solvent.

Comparative Example 1 4,4′-Diamino-4 ″-
In place of hydroxytriphenylamine,
A polyimide resin was obtained in the same manner as in Example 1, except that 4,4'-diaminotriphenylamine disclosed in JP-A-11631 was used. Table 1 shows the result of measuring the glass transition temperature of the obtained polyimide resin in the same manner as in Example 1.
Table 2 shows the solubility in solvents.

(Example 2) 3, 4, 3 ',
A polyimide resin film was obtained in the same manner as in Example 1, except that pyromellitic dianhydride was used instead of 4'-biphenyltetracarboxylic dianhydride. The infrared absorption spectrum of the polyimide resin (film), the absorption of the carbonyl group of the imide bond to 1780 cm ^-1 and 1725 cm ^-1 were observed respectively. The inherent viscosity of the obtained polyimide resin was 0.34 dl / g. The inherent viscosity of the polyamic acid is 0.2
It was 8 dl / g. When the glass transition temperature of the obtained polyimide resin was measured in the same manner as in Example 1,
As shown in Table 1, the temperature was 384 ° C., and the 10% weight loss temperature by the thermogravimeter was 489 ° C. in air and 51% in nitrogen.
1 ° C. Table 2 shows the solubility of the obtained polyimide resin in a solvent.

Comparative Example 2 4,4′-Diamino-4 ″-
In place of hydroxytriphenylamine,
A polyimide resin was obtained in the same manner as in Example 2 except that 4,4′-diaminotriphenylamine disclosed in JP-A-11631 was used. When the glass transition temperature of the obtained polyimide resin was measured in the same manner as in Example 1,
As shown in Table 1, it was not observed. Table 2 shows the solubility of the obtained polyimide resin in a solvent.

Example 3 Example 1 was repeated except that pyromellitic dianhydride of Example 2 was replaced by 3,4,3 ', 4'-diphenylethertetracarboxylic dianhydride.
A polyimide resin film was obtained in the same manner as described above. The infrared absorption spectrum of the polyimide resin (film), the absorption of the carbonyl group of the imide bond to 1780 cm ^-1 and 1725 cm ^-1 were observed respectively. The inherent viscosity of the obtained polyimide resin is 0.31 dl /
g. The inherent viscosity of the polyamic acid was 0.24 dl / g. The glass transition temperature of the obtained polyimide resin was measured in the same manner as in Example 1. As shown in Table 1, the glass transition temperature was 358 ° C., and the 10% weight loss temperature by the thermogravimeter was 475 ° C. in air. 544 ° C. in nitrogen. Table 2 shows the solubility of the obtained polyimide resin in a solvent.

Comparative Example 3 4,4′-Diamino-4 ″-
In place of hydroxytriphenylamine,
A polyimide resin was obtained in the same manner as in Example 3, except that 4,4′-diaminotriphenylamine disclosed in JP-A-11631 was used. Table 1 shows the result of measuring the glass transition temperature of the obtained polyimide resin in the same manner as in Example 1.
Table 2 shows the solubility in solvents.

Example 4 Same as Example 1 except that pyromellitic dianhydride of Example 2 was replaced by 3,4,3 ', 4'-benzophenonetetracarboxylic dianhydride. In this manner, a polyimide resin film was obtained. The infrared absorption spectrum of the polyimide resin (film), the absorption of the carbonyl group of the imide bond to 1780 cm ^-1 and 1725 cm ^-1 were observed respectively. The inherent viscosity of the obtained polyimide resin was 0.4 dl / g. The inherent viscosity of the polyamic acid is 0.46.
dl / g. The glass transition temperature of the obtained polyimide resin was measured in the same manner as in Example 1. As shown in Table 1, the glass transition temperature was 322 ° C., and the 10% weight loss temperature by the thermogravimeter was 462 ° C. in air. 526 in nitrogen
° C. Table 2 shows the solubility of the obtained polyimide resin in a solvent.

Comparative Example 4 4,4′-Diamino-4 ″-
In place of hydroxytriphenylamine,
A polyimide resin was obtained in the same manner as in Example 4 except that 4,4'-diaminotriphenylamine disclosed in JP-A-11631 was used. Table 1 shows the result of measuring the glass transition temperature of the obtained polyimide resin in the same manner as in Example 1.
Table 2 shows the solubility in solvents.

Example 5 Instead of pyromellitic dianhydride of Example 2, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexa A polyimide resin film was obtained in the same manner as in Example 1 except that fluoropropane dianhydride was used. According to the infrared absorption spectrum, 1
Absorption of the carbonyl group of the imide bond was observed at 780 cm ⁻¹ and 1725 cm ⁻¹ , respectively. The inherent viscosity of the obtained polyimide resin was 0.36 dl / g.
The inherent viscosity of the polyamic acid is 0.34 dl /
g. The glass transition temperature of the obtained polyimide resin was measured in the same manner as in Example 1. As shown in Table 1, the glass transition temperature was 343 ° C.
The weight loss temperature was 495 ° C in air and 513 ° C in nitrogen. Table 2 shows the solubility of the obtained polyimide resin in a solvent.

Comparative Example 5 4,4′-Diamino-4 ″-
In place of hydroxytriphenylamine,
A polyimide resin was obtained in the same manner as in Example 5, except that 4,4′-diaminotriphenylamine disclosed in JP-A-11631 was used. Table 1 shows the result of measuring the glass transition temperature of the obtained polyimide resin in the same manner as in Example 1.
Table 2 shows the solubility in solvents.

[0041]

[Table 1]

[0042]

[Table 2]

From Tables 1 and 2, it can be seen that the polyimide resins of the present invention of Examples 1 to 5 have a high glass transition temperature inherent to polyimide resins and are soluble in various solvents. In contrast, the polyimide resins of Comparative Examples 1 to 5 are soluble in various solvents, but have low glass transition temperatures.

[0044]

While many conventional polyimide resins have low solubility in solvents and mineral acids, they are difficult to mold, whereas the polyimide resins of the present invention use organic solvents and mineral acids. Or, it is soluble in an alkaline solution, and this solution can easily form a molded article such as a polyimide resin film, and has a high glass transition temperature and excellent heat resistance, so that it can be used as an industrial material. Great value.

Claims (4)

[Claims] 1. A polyimide resin comprising a structural unit represented by the following general formula (1). Embedded image 2. The polyimide resin according to claim 1, comprising a structural unit represented by the following formula (2). Embedded image 3. 0.5 g / d in 98% concentrated sulfuric acid at 30 ° C.
Inherent viscosity measured at a concentration of 1 to 3 dl
/G./g.
The polyimide resin as described. 4. A composition comprising 30% or more of the structural unit represented by the general formula (1) according to claim 1, and the remainder comprising a structural unit derived from 4,4′-diaminotriphenylamine. Polyimide resin.